Lepton flavor violation in $\tau$ decays

Abstract

We study the lepton flavor violation (LFV) in tau decays in the framework of the supersymmetric seesaw mechanism with nonholomorphic terms for the lepton sector at a large $\tan \beta$. In particular, we analyze two new decay modes $\tau \to \ell f_0(980)$ and $\tau \to \ell K^{+}{K}^{-}$ arising from the scalar boson exchanges contrast to $\tau \to \ell {\eta }^{(\prime )}$ from the pseudoscalar ones. We find that the decay branching ratios of the two new modes could be not only as large as the current upper limits of $O(10^{-7})$, but also larger than those of $\tau \to \ell {\eta }^{(\prime )}$. Experimental searches for the two modes are important for the LFV induced by the scalar-mediated mechanism. In addition, we show that the decay branching ratios of $\tau \to \ell {\mu }^{+}{\mu }^{-}$ are related to those of $\tau \to \ell \eta$ and $\tau \to \ell f_0(980)$.

Comments: 11 pages, 3 figures, typos corrected, references added, version to fit journal